Create cuda utils module

[multiphaseCFD]

Before submitting

Please complete the following checklist when submitting a PR:

• All new features must include a unit test.
  If you've fixed a bug or added code that should be tested, add a test to the
  tests directory!

• All new functions and code must be clearly commented and documented.
  If you do make documentation changes, make sure that the docs build and
  render correctly by running make docs.

• Ensure that the test suite passes, by running make test.

• Add a new entry to the .github/CHANGELOG.md file, summarizing the
  change, and including a link back to the PR.

• Ensure that code is properly formatted by running make format.

When all the above are checked, delete everything above the dashed
line and fill in the pull request template.

---

Context:

Create CUDA_Utils module

Description of the Change:

All the common components (in lightning_gpu/utils/) that can be shared with other cuda-based backend are move to /src/utils/cuda_utils/.

Note that the lightning_gpu_util is still kept to not break the cmake script. lightning_gpu_utils is only required for C++ layer unit tests of lightning_gpu after applying changes in this PR.

Benefits:

Possible Drawbacks:

Related GitHub Issues:

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.06%. Comparing base (8ee3e00) to head (963f3ef).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #676      +/-   ##
==========================================
+ Coverage   97.10%   99.06%   +1.96%     
==========================================
  Files         150      207      +57     
  Lines       19410    29454   +10044     
==========================================
+ Hits        18848    29180   +10332     
+ Misses        562      274     -288     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[maliasadi]

Thanks @multiphaseCFD! Just a few minor suggestions, but it should be good to merge at any time.

[vincentmr]

Nice review by @maliasadi , I don't have much to add here. LGTM, but maybe we can simplify a bit by including CUDA utils conditionally in the generic utils.

[multiphaseCFD]

Nice review by @maliasadi , I don't have much to add here. LGTM, but maybe we can simplify a bit by including CUDA utils conditionally in the generic utils.

Thanks @vincentmr ! Agree and just update the PR by linking cuda_utils to lightning_utils.

[maliasadi]

Thanks @multiphaseCFD! 🏗️